vgmstream/src/meta/ffmpeg.c

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#include "../vgmstream.h"
#include "meta.h"
#include "../util.h"
#ifdef VGM_USE_FFMPEG
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/* internal sizes, can be any value */
#define FFMPEG_DEFAULT_BLOCK_SIZE 2048
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#define FFMPEG_DEFAULT_IO_BUFFER_SIZE 128 * 1024
static int init_seek(ffmpeg_codec_data * data);
static volatile int g_ffmpeg_initialized = 0;
/*
* Global FFmpeg init
*/
static void g_init_ffmpeg()
{
if (g_ffmpeg_initialized == 1)
{
while (g_ffmpeg_initialized < 2);
}
else if (g_ffmpeg_initialized == 0)
{
g_ffmpeg_initialized = 1;
av_log_set_flags(AV_LOG_SKIP_REPEATED);
av_log_set_level(AV_LOG_ERROR);
av_register_all();
g_ffmpeg_initialized = 2;
}
}
/**
* Generic init FFmpeg and vgmstream for any file supported by FFmpeg.
* Always called by vgmstream when trying to identify the file type (if the player allows it).
*/
VGMSTREAM * init_vgmstream_ffmpeg(STREAMFILE *streamFile) {
return init_vgmstream_ffmpeg_offset( streamFile, 0, streamFile->get_size(streamFile) );
}
VGMSTREAM * init_vgmstream_ffmpeg_offset(STREAMFILE *streamFile, uint64_t start, uint64_t size) {
VGMSTREAM *vgmstream = NULL;
ffmpeg_codec_data *data = init_ffmpeg_offset(streamFile, start, size);
if (!data) return NULL;
vgmstream = allocate_vgmstream(data->channels, 0);
if (!vgmstream) goto fail;
vgmstream->loop_flag = 0;
vgmstream->codec_data = data;
vgmstream->channels = data->channels;
vgmstream->sample_rate = data->sampleRate;
vgmstream->num_samples = data->totalFrames;
vgmstream->coding_type = coding_FFmpeg;
vgmstream->layout_type = layout_none;
vgmstream->meta_type = meta_FFmpeg;
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/* this may happen for some streams */
if (vgmstream->num_samples <= 0)
goto fail;
return vgmstream;
fail:
free_ffmpeg(data);
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if (vgmstream) {
vgmstream->codec_data = NULL;
close_vgmstream(vgmstream);
}
return NULL;
}
/**
* AVIO callback: read stream, skipping external headers if needed
*/
static int ffmpeg_read(void *opaque, uint8_t *buf, int buf_size)
{
ffmpeg_codec_data *data = (ffmpeg_codec_data *) opaque;
uint64_t offset = data->offset;
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int max_to_copy = 0;
int ret;
if (data->header_insert_block) {
if (offset < data->header_size) {
max_to_copy = (int)(data->header_size - offset);
if (max_to_copy > buf_size) {
max_to_copy = buf_size;
}
memcpy(buf, data->header_insert_block + offset, max_to_copy);
buf += max_to_copy;
buf_size -= max_to_copy;
offset += max_to_copy;
if (!buf_size) {
data->offset = offset;
return max_to_copy;
}
}
offset -= data->header_size;
}
ret = read_streamfile(buf, offset + data->start, buf_size, data->streamfile);
if (ret > 0) {
offset += ret;
if (data->header_insert_block) {
ret += max_to_copy;
}
}
if (data->header_insert_block) {
offset += data->header_size;
}
data->offset = offset;
return ret;
}
/**
* AVIO callback: write stream not needed
*/
static int ffmpeg_write(void *opaque, uint8_t *buf, int buf_size)
{
return -1;
}
/**
* AVIO callback: seek stream, skipping external headers if needed
*/
static int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence)
{
ffmpeg_codec_data *data = (ffmpeg_codec_data *) opaque;
if (whence & AVSEEK_SIZE) {
return data->size + data->header_size;
}
whence &= ~(AVSEEK_SIZE | AVSEEK_FORCE);
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/* false offsets, on reads data->start will be added */
switch (whence) {
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case SEEK_SET:
break;
case SEEK_CUR:
offset += data->offset;
break;
case SEEK_END:
offset += data->size;
if (data->header_insert_block)
offset += data->header_size;
break;
}
if (offset > data->size + data->header_size)
offset = data->size + data->header_size;
return data->offset = offset;
}
/**
* Manually init FFmpeg only, from an offset.
* Can be used if the stream has an extra header over data recognized by FFmpeg.
*/
ffmpeg_codec_data * init_ffmpeg_offset(STREAMFILE *streamFile, uint64_t start, uint64_t size) {
return init_ffmpeg_faux_riff(streamFile, -1, start, size, 0);
}
/**
* Manually init FFmpeg only, from an offset / fake RIFF.
* Can insert a fake RIFF header, to trick FFmpeg into demuxing/decoding the stream.
*/
ffmpeg_codec_data * init_ffmpeg_faux_riff(STREAMFILE *streamFile, int64_t fmt_offset, uint64_t start, uint64_t size, int big_endian) {
char filename[PATH_LIMIT];
ffmpeg_codec_data * data;
int errcode, i;
int streamIndex;
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AVStream *stream;
AVCodecParameters *codecPar;
AVRational tb;
/* basic setup */
g_init_ffmpeg();
data = ( ffmpeg_codec_data * ) calloc(1, sizeof(ffmpeg_codec_data));
if (!data) return NULL;
streamFile->get_name( streamFile, filename, sizeof(filename) );
data->streamfile = streamFile->open(streamFile, filename, STREAMFILE_DEFAULT_BUFFER_SIZE);
if (!data->streamfile) goto fail;
data->start = start;
data->size = size;
/* insert fake RIFF header to trick FFmpeg into demuxing/decoding the stream */
if (fmt_offset > 0) {
int max_header_size = (int)(start - fmt_offset);
uint8_t *p;
if (max_header_size < 18) goto fail;
data->header_insert_block = p = av_malloc(max_header_size + 8 + 4 + 8 + 8);
if (!data->header_insert_block) goto fail;
if (read_streamfile(p + 8 + 4 + 8, fmt_offset, max_header_size, streamFile) != max_header_size) goto fail;
if (big_endian) {
p += 8 + 4 + 8;
put_16bitLE(p, get_16bitBE(p));
put_16bitLE(p + 2, get_16bitBE(p + 2));
put_32bitLE(p + 4, get_32bitBE(p + 4));
put_32bitLE(p + 8, get_32bitBE(p + 8));
put_16bitLE(p + 12, get_16bitBE(p + 12));
put_16bitLE(p + 14, get_16bitBE(p + 14));
put_16bitLE(p + 16, get_16bitBE(p + 16));
p -= 8 + 4 + 8;
}
data->header_size = 8 + 4 + 8 + 8 + 18 + get_16bitLE(p + 8 + 4 + 8 + 16);
// Meh, dunno how to handle swapping the extra data
// FFmpeg doesn't need most of this data anyway
if ((unsigned)(get_16bitLE(p + 8 + 4 + 8) - 0x165) < 2)
memset(p + 8 + 4 + 8 + 18, 0, 34);
// Fill out the RIFF structure
memcpy(p, "RIFF", 4);
put_32bitLE(p + 4, data->header_size + size - 8);
memcpy(p + 8, "WAVE", 4);
memcpy(p + 12, "fmt ", 4);
put_32bitLE(p + 16, 18 + get_16bitLE(p + 8 + 4 + 8 + 16));
memcpy(p + data->header_size - 8, "data", 4);
put_32bitLE(p + data->header_size - 4, size);
}
/* setup IO, attempt to autodetect format and gather some info */
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data->buffer = av_malloc(FFMPEG_DEFAULT_IO_BUFFER_SIZE);
if (!data->buffer) goto fail;
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data->ioCtx = avio_alloc_context(data->buffer, FFMPEG_DEFAULT_IO_BUFFER_SIZE, 0, data, ffmpeg_read, ffmpeg_write, ffmpeg_seek);
if (!data->ioCtx) goto fail;
data->formatCtx = avformat_alloc_context();
if (!data->formatCtx) goto fail;
data->formatCtx->pb = data->ioCtx;
if ((errcode = avformat_open_input(&data->formatCtx, "", NULL, NULL)) < 0) goto fail; /* autodetect */
if ((errcode = avformat_find_stream_info(data->formatCtx, NULL)) < 0) goto fail;
/* find valid audio stream inside */
streamIndex = -1;
for (i = 0; i < data->formatCtx->nb_streams; ++i) {
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stream = data->formatCtx->streams[i];
codecPar = stream->codecpar;
if (streamIndex < 0 && codecPar->codec_type == AVMEDIA_TYPE_AUDIO) {
streamIndex = i; /* select first audio stream found */
} else {
stream->discard = AVDISCARD_ALL; /* disable demuxing unneded streams */
}
}
if (streamIndex < 0) goto fail;
data->streamIndex = streamIndex;
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stream = data->formatCtx->streams[streamIndex];
/* prepare codec and frame/packet buffers */
data->codecCtx = avcodec_alloc_context3(NULL);
if (!data->codecCtx) goto fail;
if ((errcode = avcodec_parameters_to_context(data->codecCtx, codecPar)) < 0) goto fail;
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av_codec_set_pkt_timebase(data->codecCtx, stream->time_base);
data->codec = avcodec_find_decoder(data->codecCtx->codec_id);
if (!data->codec) goto fail;
if ((errcode = avcodec_open2(data->codecCtx, data->codec, NULL)) < 0) goto fail;
data->lastDecodedFrame = av_frame_alloc();
if (!data->lastDecodedFrame) goto fail;
av_frame_unref(data->lastDecodedFrame);
data->lastReadPacket = malloc(sizeof(AVPacket));
if (!data->lastReadPacket) goto fail;
av_new_packet(data->lastReadPacket, 0);
data->readNextPacket = 1;
data->bytesConsumedFromDecodedFrame = INT_MAX;
/* other setup */
data->sampleRate = data->codecCtx->sample_rate;
data->channels = data->codecCtx->channels;
data->floatingPoint = 0;
switch (data->codecCtx->sample_fmt) {
case AV_SAMPLE_FMT_U8:
case AV_SAMPLE_FMT_U8P:
data->bitsPerSample = 8;
break;
case AV_SAMPLE_FMT_S16:
case AV_SAMPLE_FMT_S16P:
data->bitsPerSample = 16;
break;
case AV_SAMPLE_FMT_S32:
case AV_SAMPLE_FMT_S32P:
data->bitsPerSample = 32;
break;
case AV_SAMPLE_FMT_FLT:
case AV_SAMPLE_FMT_FLTP:
data->bitsPerSample = 32;
data->floatingPoint = 1;
break;
case AV_SAMPLE_FMT_DBL:
case AV_SAMPLE_FMT_DBLP:
data->bitsPerSample = 64;
data->floatingPoint = 1;
break;
default:
goto fail;
}
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data->bitrate = (int)(data->codecCtx->bit_rate);
data->framesRead = 0;
data->endOfStream = 0;
data->endOfAudio = 0;
/* try to guess frames/samples (duration isn't always set) */
tb.num = 1; tb.den = data->codecCtx->sample_rate;
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data->totalFrames = av_rescale_q(stream->duration, stream->time_base, tb);
if (data->totalFrames < 0)
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data->totalFrames = 0; /* caller must consider this */
/* setup decode buffer */
data->samplesPerBlock = FFMPEG_DEFAULT_BLOCK_SIZE;
data->sampleBuffer = av_malloc( data->samplesPerBlock * (data->bitsPerSample / 8) * data->channels );
if (!data->sampleBuffer)
goto fail;
/* setup decent seeking for faulty formats */
errcode = init_seek(data);
if (errcode < 0) goto fail;
return data;
fail:
free_ffmpeg(data);
return NULL;
}
/**
* Special patching for FFmpeg's buggy seek code.
*
* To seek with avformat_seek_file/av_seek_frame, FFmpeg's demuxers can implement read_seek2 (newest API)
* or read_seek (older API), with various search modes. If none are available it will use seek_frame_generic,
* which manually reads frame by frame until the selected timestamp. However, the prev frame will be consumed
* (so after seeking to 0 next av_read_frame will actually give the second frame and so on).
*
* Fortunately seek_frame_generic can use an index to find the correct position. This function reads the
* first frame/packet and sets up index to timestamp 0. This ensures faulty demuxers will seek to 0 correctly.
* Some formats may not seek to 0 even with this though.
*/
static int init_seek(ffmpeg_codec_data * data) {
int ret, found = 0;
int64_t ts = 0;
AVStream * stream;
AVPacket * pkt;
/* read_seek wouldn't use the index, but direct access to FFmpeg's internals is no good */
/* if (data->formatCtx->iformat->read_seek || data->formatCtx->iformat->read_seek2)
return; */
pkt = data->lastReadPacket;
/* find the first packet */
while (!found) {
av_packet_unref(pkt);
ret = av_read_frame(data->formatCtx, pkt);
if (ret < 0)
break;
if (pkt->stream_index != data->streamIndex)
continue; /* ignore non-selected streams */
found = 1;
}
if (!found)
return -1;
/* add index 0 */
stream = data->formatCtx->streams[data->streamIndex];
ret = av_add_index_entry(stream, pkt->pos, ts, pkt->size, 0, AVINDEX_KEYFRAME);
if ( ret < 0 )
return ret;
/* move back to beginning, since we just consumed packets */
ret = avformat_seek_file(data->formatCtx, data->streamIndex, ts, ts, ts, AVSEEK_FLAG_ANY);
if ( ret < 0 )
return ret; /* we can't even reset_vgmstream the file */
avcodec_flush_buffers(data->codecCtx);
return 0;
}
void free_ffmpeg(ffmpeg_codec_data *data) {
if (data->lastReadPacket) {
av_packet_unref(data->lastReadPacket);
free(data->lastReadPacket);
data->lastReadPacket = NULL;
}
if (data->lastDecodedFrame) {
av_free(data->lastDecodedFrame);
data->lastDecodedFrame = NULL;
}
if (data->codecCtx) {
avcodec_close(data->codecCtx);
avcodec_free_context(&(data->codecCtx));
data->codecCtx = NULL;
}
if (data->formatCtx) {
avformat_close_input(&(data->formatCtx));
data->formatCtx = NULL;
}
if (data->ioCtx) {
// buffer passed in is occasionally freed and replaced.
// the replacement must be freed as well.
data->buffer = data->ioCtx->buffer;
av_free(data->ioCtx);
data->ioCtx = NULL;
}
if (data->buffer) {
av_free(data->buffer);
data->buffer = NULL;
}
if (data->sampleBuffer) {
av_free(data->sampleBuffer);
data->sampleBuffer = NULL;
}
if (data->header_insert_block) {
av_free(data->header_insert_block);
data->header_insert_block = NULL;
}
if (data->streamfile) {
close_streamfile(data->streamfile);
data->streamfile = NULL;
}
free(data);
}
#endif